Process for manufacturing ammonium sulphate or salts containing it



, gnoojnss r03 Mmw irct ame m sULrHA'rE, ontsAIl'rs oonirAr n f Patexitedhlovisolution of ammonium sulphate "containing or'inot'containing salts of 'alkalis orisalts of alkaline earth metals and in subjectingfsaid solution'to the act1onof oxygenor gasjes containing oxygen under the normal or -ahigh" pressure through contact, and thej invention has forit's object to manufactureammonium sulphate'or saltscontaining it incrystalline form in a simple and economical manner simply by oxidizing ammonium fsulphite in the solution without evaporating orfcon'centrating operation. a 3 a n U p After years of researches, the inventorhas discovered" that the velocity of catalytic oxidation of ammonium sulphite in the solution: with oxygen or gases containing ox en depends much on the composition ots'a'id solution, for example, when concentrations of ammonia andsulphurous acid in the solue' tion are equivalent, that is to say, when they are'in the same proportion a's in'theflcase of ammonia and sulphurdioxidelin(NIL) g, the velocity is greatest. When the 'concen tration of ammonia exceeds'said value, the velocity decreases considerably. Theiexcess of, sulphur dioxide affects little. The in-; crease of the concentration of ammonium sulphite reduces the velocity'considerably, While the effect of ammonium sulphate in solution is small. It is because ammonium sulphate is stable, while ammonium sulphite is unstable so that it decomposes by hydroly sis and hinders the oxidation. The higher the concentration of ammonium 'sulphiteis, the more the oxidation is hindered. In short, the velocity of the oxidation of amnonium sulphite of a given concentration is considerably retarded by ammonia, less re tarded by ammonium sulphite,and far less retarded by sulphurous acid, and. least retarded by ammonium sulphate. Based on these facts, the process described in this specificationhas been invented by e A. process has been known to OXldlZe dilute watersolution of ammonium sulphite.

' application n Qctober 12s, 1930." semi Kai-490,225,

accordingv'tof this processfthe oxidation of concentrated water solut on of ammonium scale; TI). 1

which has not been oxidized; andlis'infan un;

According tothis process expensiveevap; Ora-ting and concentrating" operations la'refre' w quiredjin order to obtainaminon'ium sulphate "in 1 crystalline form, although, the xidation can be efiectedin a shortjtime Another-process has beenwiiled p from' concentrated water "solution. [of moniiim sulphite' and toxc'onvert' it-tel solution of ammonininjsulphate of s uch con centration as to :re'ducerthe costjofev'aporat- 169 ing 'fand concentrating operations, However,

sulphite -'requ'ires"much time. Because of,

these defects, the manufactu're of'a'mmonium sulphateby oxidiz'ing ammoniuin,sulphite in water'solution hasnotbeenjdone-one large According to tliis invention, ammonii1m sulphite is dissolved'in saturatedwater solu; 79 f tion of ammoniuin sulphate containing or not containing salts of alkallsor saltsyef alkaline earth metals ammonium" V sul,. I phite in said solutionis oxidized cataly'ticallyj with ,aoxygen .or j'gases' containing "oxygena 5 7 Andthen ammonium sulphiteiis converted to 7 ammonium sulphate which. immediately crystallizesffrom the 7 mother liquor, whereby expensive evaporating jorconcentrating' operation can be done away with. In this 3 mmonium Qsulphatefofcrystalline manner,-j fo'rmTcan-be' produced at a low cost. In theknown processes, ammonium sul hite stable state is lost through'de coinposition (lur I ing the evaporati g-er concentratingeoperartioni "Therefore, theioxidation should be e'f- 1 rected eom ieteiy and nalyze s; i5 weak strength can not be used; fIn'the prese phite oxidized to ammonium- 'sulphate -wil-l crystallize so that there will be not loss -o f it, v Therefore, catalyzers-of weak strengthjfsuch as salts" ofcopper, nickehfor iron canbe. used but of strong nomicjally; 1

se erman a li Jess, on the contrary, only the ammonium suL,

compressed onygen or gases containing oxygenis' employed, the oxidation of am monium sulphite in the solution will be elfect so astofacilitatethe ope-ration.

ith. certaini kinds of the added saltspcom 'plex or double salts of ammonium sulphate I are produced which may serve as mixedma- Suchfsalts-"are potassium sulphate;

gases con ainingjoxygen may be blowninto :I t he solution in bubbles or the solutionmaybe spr y iin ethe-ga s in fi ei s e -1 'Ifjanimoniu'm' sulphite is supplied gradual1y;jii 1 to,, the I oxidizing apparatus containin'g fconcentrate'd solution vof ammonium sulphate- ,With 'or Without salts of al'kalis or salts or alkaline earth metals, the concentration of ammonium isulphite in the solutionfwill be keptnlow so as to facilitate the reaction.

Besides. ammonium sulphite, acid: gammo nium sulphlte and ammon1a' may,beused,- or

- ,Water solution of sulphurous'acid and ammonia may be supplied into the oxidizing appa ratu s separately,; or sulphur. dioxide, ammo- 'nia, and ater-may be supplied into the oxidizing: apparatus. In short}. the materials to be used may be in;liquid,zgafseous, solid or dis:- so lvedstateiand' may be supplied into the oxidining; apparatus 'separatelv or in combina-V tiOIl In thislsystem' ammonium sulphate or salts containingjit deposit in the oxidizing.

I another system; after the completion of v I the, oxidation,thefammonium sulphate'solue tion obtainedis removed into another; ;appai r-atus, and thenyby cooling or dissolving am-e 0 is lrea; goodw c ta t, oxygen am bnium alp a; and in subjecting said" solution to the action of ox ygen under "pres" sure in the presence of' catalyzers.

sulphate or salts 1 containing the; s'ame, con- 2," Process .fofmanufacturin ammonium sisting in dissolving ammonium sulphite in V saturated solutionof ammonium sulphate containing saltsfofalkalis While maintaining the proportion between am'monia and' sula phu r ous acid containedtherein in such'a pro portionthatthey form normal" ammonium: v sulphite'; a small excess of sulphurous-acid ii existing. beside n'orn'ial:ammoniumisulphite;

and in subjecting said solution tdtheaction of; oxygen .underpressure in the prefsence of catalyzers. q

3. Process rated solution of ammonium sulphatecontain 7 for manufacturing ammonium f i sulphateor; salts'conta n ng the'sa-me, consist ing in'dissolvlngammoniumsulphlteinsatua 85 .e ns s a kal ne ert mef lsrw lemain? tamingthe -proportlonbetween ammon a-and sulphur'ous acid containedthereinin such-ia thatthey normal ammonium sulph1te, a small excess of s'ulphurous acid existing bes de normal ammonium sulphite;

and in subjecting said solution to thejaction of 7 oxygenfunder pressurein the presence 10f A. Process for manufacturing ammonium sulphate or salts containmg the same, consistin dissolving annnonium'sulphiteinsatutaming the proportion between ammonia and rated solution of ammonium sulphate containng saltsof alkaline earth metals, While main- 7 I su-lphurous acid containedltherein in such a and in; subjecting said solution to the action of gases containingoxygenflunder high pressure iii-the presence ofcatalyzers;

: testimony' whereof. I hereunto aflix' signature. r

moniumsulphite or"itsi constituents crystal- I r 0Sited"7 e m 2, 1

v sep r ti g:rhefleposits therefrom" a thefiltllatemay'beufied a i-in'the oxidizing apparatus, -v a 7 line amm n msi ph t s s on a n g" it:

11:H n m p-manna described and ascertained .then'aftur'e of my said invention, andin-iWhat-ma 'e th i m fi 569 1 1 formed, declare that what I claim is :1 -'.',:The processfor manufacturing amm0ni.-. p

um sulphate or saltscontammg the same', con- T e' S isting-in dissolvingjammoniuinsulphite in saturatedsolution fof ammonium-sulphate {while maintaining theproportion between; i.

mmonia; "and 1111 hu s; a d contained ,therein in; suchfproportjion that they form' rmel'emm nium.,sulph e J m ii} I of sulphurous acidex stmg besldeirnormal I proportionthat they formno'rmal ammonium 1 sulphite, a small excess-of ,sulphurousfacid exist ng. besidenormal ammonium sulphite'; 

